The invention relates to a computer system in which a population of computers has access to multiple software applications. The computers may be personal computers (PC's) or, for example, integrated circuit cards (“IC cards”), also known as “smart cards”. The applications may be programs available from a variety of sources, including computer tape or disc, and, in particular, remote computers with which a serial link, typically by telephone, is established.
In the PC environment, it is customary to distribute applications on floppy discs or CD ROMS and to retain them on a local hard disc for operation. In many ways, this is inconvenient, demanding high capacity local storage media and presenting difficulties with updates. In the field of smart cards, the problem of local application storage is much more acute, because storage capacity in the integrated circuit is relatively very limited. A solution in both cases is to make available applications held remotely and download them via a remote link. Internet and intranet systems are ideal vehicles for this, and it is possible to run PC's from Internet application modules (or “applets” as they are called) for immediate running and then to discard the applets. The applets require no local long-term storage capacity. An example of such a system is JAVA.
Several difficulties are associated with downloaded applications. One is hardware compatibility. Different computers have different microprocessors and different operating systems. It has been customary to re-write applications to cater to different computers, but this is cost-effective only for large, widely used, and static applications. It is not practicable for applets. A second problem is control of the applets. Without control, it would be possible for applets to make direct hardware calls to take control of local storage or communication devices. This could be mischievous at best and severely damaging or criminal at worst.
JAVA meets these two difficulties by ensuring that the applets are written in a common high-level interpreted language and that a local interpreter processes the applet instructions. Thus, all applets are written in the same language, and the interpreter constitutes both a hardware buffer and a control buffer. Similarly, and for the same reasons, proposals have been made for on-board interpreters in smart cards to run downloaded high-level language applications.
The wide availability of multiple applications to a population of computers raises another problem. For various reasons, it may be desirable to restrict the availability of certain applications to certain computers. For example, some applications may make demands which the hardware of a particular computer cannot meet. These represent technical limitations present in spite of the interpreter arrangement. Furthermore, there may be commercial or moral restraints to be placed on the accessibility of certain applications to certain computers. The present invention seeks to provide a solution to this problem.
IC cards are becoming increasingly used for many different purposes in the world today. An IC card typically contains a computer chip including a microprocessor, read-only-memory (ROM), electronically erasable programmable read only memory (EEPROM), an Input/Output (I/O) mechanism, and other circuitry to support the microprocessor in its operations. An IC card may contain a single application or may contain multiple independent applications in its memory. MULTOS™ is a multiple application operating system which runs on IC cards, among other platforms, and allows multiple applications to be executed on the IC card itself. This allows a card user to run many programs stored in the IC card (for example, credit/debit, electronic money/purse, and/or loyalty applications), irrespective of the type of terminal (i.e., ATM, telephone, and/or POS) in which the IC card is inserted for use.
A conventional single application IC card, such as a telephone card or an electronic cash card, is loaded with a single application at its personalization stage when it is manufactured and before it is given to a card user. That application, however, cannot be modified or changed after the IC card is issued, even if the modification is desired by the IC card user or issuer. Moreover, if a card user wanted a variety of application functions to be performed by IC cards issued to him or her, such as both an electronic purse and a credit/debit function, the card user would be required to carry multiple physical cards on his or her person, which would be quite cumbersome and inconvenient. If an application developer or card user desired two different applications to interact or exchange data with each other, such as a purse application interacting with a frequent flyer loyalty application, the card user would be forced to swap multiple cards in and out of the card-receiving terminal, making the transaction difficult, lengthy, and inconvenient.
Therefore, it is beneficial to store multiple applications on the same IC card. For example, a card user may have both a purse application and a credit/debit application on the same IC card, so that the user could select which type of payment (by electronic cash or credit card) to use to make a purchase. Multiple applications could be provided to an IC card if sufficient memory exists and an operating system capable of supporting multiple applications is present on the IC card. Although multiple applications could be preselected and placed in the memory of the IC card during its production stage, it would also be beneficial to have the ability to load and delete applications for the IC card post-production as needed.
The increased flexibility and power of storing multiple applications on a single IC card create new challenges to be overcome concerning the integrity and security of the information (including application code and associated data) exchanged between the individual IC card and the application provider, as well as within the entire system when loading and deleting applications. It would be beneficial to have the capability in the IC card system to exchange data among IC cards, IC card issuers, system operators and application providers securely and to load and delete applications securely at any time from a local terminal or remotely over a telephone line, Internet, or intranet connection or other data conduit. Because these data transmission lines are not typically secure lines, a number of security and entity authentication techniques must be implemented to make sure that applications being sent over the transmission lines are not tampered with and are loaded onto the intended IC cards only.
As mentioned, it is important—particularly where there is a continuing wide availability of new applications to the cardholder—that the system has the capability of adding applications onto the IC card subsequent to issuance. This is necessary to protect the longevity of the IC cards; otherwise, once an application becomes outdated, the IC card would be useless. It would be beneficial to allow the addition of applications from a remote location as well as from a direct connection to an application provider's terminal. For example, it would be beneficial for a card user to be able to plug his or her IC card into a home computer and download an application over the Internet. This type of remote loading of applications raises a number of security risks when transmitting the application code and related data over an unsecured communications line such as the Internet. Several issues need to be addressed in a system which provides such a capability.
One issue is to make sure that the IC card receiving the application is the intended IC card and not another IC card. A second issue is determining how the IC card can authenticate that the application came from the proper application provider and not an unknown third party. A third issue concerns preventing third parties from reading the application and making an unauthorized copy. If a portion of the application is encrypted to address the latter issue, the intended IC card needs to have access to the correct key to decrypt the application. In a system with many IC cards and additionally many application providers, a secure key transfer technique is required so that the intended IC card can use the correct key for the application which is received. Since the application provider and the IC card issuer will not, generally, be the same entity, the need also arises to protect the confidentiality of the application provider's data from the card issuer. These concerns are raised by both remote application loading as well as by local terminal application loading.
Accordingly, it is an object of this invention to provide secure transfer techniques, specifically, to provide a secure IC card system that allows for the transfer of data from a software application provider to an IC card while securing the proprietary data of application providers from, for example, inspection or copying by the IC card issuer.
According to the invention, a computer system comprises a population of computers; tamper-resistant modules each associated respectively with one of said computers; a plurality of computer applications; provider means for holding the computer applications; and means for coupling the provider means to the computers for downloading the computer applications to the computers.
The computers may be personal computers (PC's) or any other types of computers, in which case the tamper-resistant modules may be smart cards read by readers coupled to the computers or installed as Subscriber Identity Modules (SIM's) in mobile telephones or, for example, dongles, PC cards, or PCMCIA cards coupled to the computers. Furthermore, although the following description of the preferred embodiments revolves around a discussion of IC cards (or “smart cards”), the presently claimed methods and apparati are applicable to all tamper resistant modules generally, and not just to such cards. Thus, the term “tamper resistant module” can be used in lieu of the term “IC card” or “smart card” throughout this written description. The term “tamper resistant module” includes, but is not limited to, one or more IC cards, smart cards, SIM's, dongles, PC cards, and/or PCMCIA cards. The IC cards, smart cards, SIM's dongles, PC cards, and/or PCMCIA cards may be coupled to one or more computers or mobile phones.